Hypertension remains a major public health problem. Several studies support the theory that the roots of essential hypertension may extend back to childhood. With obesity reaching epidemic proportions and youth obesity being one of the strongest predictor of young adulthood hypertension, little empirical information is available on secular changes in the prevalence of hypertension in youth. Current data on secular trends of blood pressure in this age group are sparse and inconsistent. The proposed 2-year secondary analysis of the US national survey data addresses this issue with the following aims: 1. (a) To describe the trends in age-adjusted mean systolic blood pressure, diastolic blood pressure, and pulse pressure and the age-adjusted prevalence of hypertension for all boys and girls, 6-17 years of age; (b) To describe these trends separately for African-American and White participants. 2. To evaluate whether these trends are modified or partially explained by obesity, as assessed by body-mass-index, the ratio of triceps over subscapular skinfold thickness, and percent body fat. 3. To evaluate whether the correlation of blood pressure with obesity is modified or explained by dietary and blood antioxidant levels. The study population will consist of 6 to 17 year old participants in NHES II through NHANES IV-Phase I Surveys (1963-2000). These surveys were conducted by the National Center for Health Statistics on a nationwide probability sample, based on a complex multistage sample design to provide national estimates of health and nutritional status of the civilian noninstitutionalized population of the United States aged 2 months and older. Weighted analyses will be used to obtain valid estimates. This study has the potential to contribute new knowledge with respect to the national burden of hypertension in youth in the face of increasing youth obesity. Studies may suggest an inflammatory etiologic component associated with hypertension, which starts in youth in obese children. Research findings would lead to more refined mechanistic studies for ultimately better tailored interventions.